NOAA aircraft studies stormy weather

By Megan Lisagor

Mar 28, 1999

The National Oceanic and Atmospheric Administration finished flying a series of high-tech missions over the Pacific Ocean earlier this year to collect data that eventually will help scientists build more accurate and timely forecasts and increase their understanding of turbulence.

The jet, which NOAA acquired in 1996, can fly up to an altitude of 45,000 feet, allowing it to cover an area where there are next to no observations being made, according to the agency.

"This is the only Gulfstream that does this kind of work," electronic engineer Juan Carlos Pradas-Bergnes said.

During the flights, the G-IV crew releases dropsondes - instruments that measure temperature, wind, moisture and pressure data - into the atmosphere. The dropsondes transmit their measurements to the jet's computers, which, in turn, process and display the data.

Sitting at computer stations, on-board scientists receive the information shortly after each dropsonde is deployed and then transmit the collected data to the National Weather Service.

The NWS puts the information into its computer models and uses it to generate more accurate predictions.

"It goes into the models right now, and they're run today," said Stan Goldenberg, a hurricane analysis and processing system operator, while on a mission in Honolulu. "We used to have a calculator who would plot it and code it. We've come a long way."

In addition to the NWS and NOAA, other agencies are benefiting from these missions. One is the Federal Aviation Administration, which is working with NOAA to learn more about weather patterns.

"If we can improve safety, we've saved money for all government agencies," pilot Mark Finke said. "[It will] certainly help the FAA."

The FAA's major concern is turbulence. Turbulence poses an extreme hazard to aircraft, sometimes causing structural damage as well as injury and even death to passengers and flight staff. In December 1998, a United Airlines flight dropped 99 feet after encountering turbulence, resulting in one death and more than 300 injuries.

Current weather systems offer no effective way to detect turbulence, forcing the FAA to rely on pilot reports about potentially danger areas. These subjective reports, however, are not always reliable.

"In the past, [information] has been derived from satellites and pilot reports, which are spotty at best," Finke said. NOAA researchers are working with the FAA, the National Center for Atmospheric Research and the Naval Research Laboratory to replace these reports with readings from numerical weather models.

"Good data means we can use these profiles to see where turbulence is forming," said Mel Shapiro, project director of the NOAA/Environmental Technology Laboratory. "We're able to reduce the forecast error by 10 to 15 percent."

The NOAA missions followed an incident in January, when a jetliner traveling from Japan hit turbulence, injuring 13 passengers. With these disasters in mind, the push to improve weather predictions and turbulence forecasts seems more than worthwhile; it seems critical.

Democrats will vote on an appropriations package to reopen all the federal agencies shuttered during the partial shutdown, but the lack of wall funding will likely means the measure won't get a vote in the Senate.